Oceans: A Permanent Extreme Situation – Spectrum of Science

Between 2013 and 2015, a huge bubble of warm water – the “Blob” – occurred in the Northeast Pacific. Its effects were devastating, causing harmful algal blooms and mass die-offs of certain species, among other things. The extremely high water temperature was known from satellite measurements. Using a high-resolution ocean model, we investigated what happens to other stressors during such a warm-water bubble. In doing so, we found that the observed effects – including stranded dead fish and algal blooms – were possibly not just a result of warm water, but a consequence of various stressors. And so we put our focus on compound events.

What stressors are we talking about?

One of the factors that marine organisms are often unable to cope with is the sharp increase in water temperature. The rising air temperature due to man-made greenhouse gas emissions means that the sea is warming from top to bottom. In fact, the ocean absorbs about 90 percent of the heat stored in the Earth system from the increase in greenhouse gases…